Frederick L. Jaggi age 81, of Cranston, RI passed away in Warwick surrounded by family on Saturday, September 24th. He was born on July 2nd, 1935 in Providence, to Frederick E. and Clarice (Melvin) Jaggi. He was the husband of the late C. Valerie (Jacques) Jaggi, married for 52 years. One son Christopher preceded him in death and he is survived by two sons, Frederick P. Jaggi and his wife Tammy of Plano TX, Nicholas Jaggi and his wife Carla of Warwick, RI, and six grandchildren, Brice, Corey, Zachary, Nicholas, Ryan and Kaitlin. He studied chemistry at Brown University and graduated from the Massachusetts Institute of Technology with a Bachelor of Science degree in chemical engineering. Fred had a long and illustrious career in the petrochemical and energy industries. He completed projects all over the world. Fred and Val lived in England, France, Holland, and the US. They enjoyed travelling, spending time with their extended family, their dogs and spoiling their grandchildren. Fred actively participated in many different organizations including the MIT alumni association, New England Model Engineering Society, Waushakum Live Steamers, and the North American Sundial Society. Fred also gave generously of his time and energy to St David’s on the Hill Church, mobile loaves and fishes, Harrington House, Rhode Island Community Food Bank and the Hope Alzheimers Center. Fred was in good standing for over 50 years with the American Institute of Chemical Engineering. Fred served as the president of the New England Steam Museum, and took great joy in hand crafting complex scientific equipment including miniature steam engines, sundials and orreries. Fred was greatly loved and will be sorely missed. Horas Non Numero Nisi Serenas. “I only count the hours that are serene.” A Funeral Service will be held on Friday at 11:00am in St. Davids on the Hill Episcopal Church 200 Meshanticut Valley Parkway Cranston. Burial will be private. Visitation will be held on Thursday from 4:00-7:00pm in The Butterfield Chapel 500 Pontiac Avenue Cranston. In lieu of flowers donations to the Hope Alzheimers Center 25 Brayton Avenue Cranston 02920 or to St David’s on the Hill Episcopal Church would be appreciated.

Steam Building, pen-and-ink drawing, by Todd Cahill, commissioned by Fred's Children for his 80th birthday


Six Planet Orrery by Fred Jaggi of Cranston, RI

Following is Fred’s description.

Peter Grimwood, a present-day orrery maker, gave me a diagram and wheel layout for a planetarium representing the six planets known since antiquity. The design is in the style of Benjamin Martin of Fleet St. ca 1750. It contains 14 gears, which allow the planets to orbit the sun in a steady circular path with an orbital period within 1/10th of one percent of the actual mean period. In those days, when calculations were done by hand, makers strived to calculate gear trains that would accurately represent natural orbits and the more advanced orreries produced elliptical paths and showed more planets and their satellites.

Last winter’s project was to build Grimwood’s planetarium. Unlike a clock, most of the gears are arraigned in two stacks set at a fixed distance. A third shaft is fitted to accommodate the high gear ratio needed to represent Saturn’s orbit. Six different modules, diametral pitch (DP), were used to allow the gears to mesh correctly. I had to make a fly cutter for each of the modules. The gears were cut using a homemade ball bearing spindle made up from pipe fittings and a dividing head. The tooth numbers on two of the gears are prime. For these, I pasted Excel spreadsheet grids on wooden disks attached to the dividing head. James E. Morrison adapted one of his astrolabe programs for my dial. I first thought about having the dial laser engraved locally, but the engravers said they were not able to laser engrave brass. I then turned to Hockerill Engraving in Devon, England who produced an inexpensive brass dial by chemical etching, which I then silvered. The dial has deep, sharp indentations, equivalent to mechanical engraving.

One turn of the dial represents two weeks motion and it’s fun to watch Mercury race around in 87 days while Saturn moves at the almost imperceptible rate of nearly 30 years.